Arc extinguishing chamber for circuit breakers



. 3, 1946. G; w. PETERS 4 ARC EXTINGUISHING CHAMBER FOR CIRCUIT BREAKERSFiled Feb. 9, 1944 2 Sheets-Sheet 1 -MoqA/fr Dec. 3, 1946. G. w. PETERS2,411,894

ARC EXTINGUISHING CHAMBER FOR CIRCUIT BREAKERS Filed Feb. 9. 1944 2sheets-snee: 2

0 5 Z 6 2 4 3 f \4\\( A ////////////J///J///////////// leraar/NG256mo-m7 Patented Dec. 3, 1946' ARC EXTINGUI'SHING CHAMBER FOR CIRCUITBREAKERS Gerhard W.Peters, Akron, Ohio Application February 9, 1944,serial No. 521,613

My invention relates in general to electric switches and moreparticularly to quick-acting circuit interrupting switches which may beactuated electro-magnetically or otherwise.

An object of my invention is the provision of a split insulating housinghaving an arc chamber for an electric switch having stationary contactmeans mounted upon one ofthe parts of the split housing and having themovable contact means projecting into an opening through the other partof the split insulating housing, the contact means and the splitinsulating housing means being so arranged that when the part having theopening therein is removed, the stationary contact means becomes readilyexposed and accessible for inspection and replacement.

Another object of my invention is the provision of preventing theremoval oi one of the parts of the split insulating housing when themovable contacts are in their operative motion transmitting position.

Another object .of my invention is to prevent` the removal of one of theparts oi the split insulating housing the motion transmitting meanswhich operate them are tlrst removed.

Another object of my invention is the provision of resilient meansinterposed between the movable contact means and the actuatingmechanism, the resilient means being so disposed that it is mountedexternally of the insulating housing to be free from the arc in theinsulating housing.

Another object of my invention is to prevent the movable contact meansduring the circuit interrupting movement from being withdrawn from theopening in the insulating housing in which the movable contact meansoperates.

Another object of my invention is the provision rst separated in thelarge chamber, after which the movable contact immediately moves intothe small chamber, the movable contact being arrest ed in its separatingmovement in the small cham ber, or at least prior to a point where thearea between the movable contacts and the side wall of the small chamberequals the cross-sectional area of the small chamber. J

Another object of my invention is to provide a housing having a largechamber in which the stationary contact is mounted and having a smallerchamber connecting the large chamber with the outside of the housingforming an opening through which the movable contact is actuated toengage the stationary contact.

unless the movable contacts and 3 Claims. (Cl. 20D-144) 2 Another objectof my invention is the provision of detachably removing the movablecontact means without removing the insulating housing. Other objectsanda fuller understanding of the invention may be had by referring to thefollowing description and claims, taken in conjunction with theaccompanying drawings, in which:

Figure 1 is a top view of a switch embodying the features of myinvention;

Figure 2 is a front elevational view of the deviceshown in Figure 1 withcertain parts broken away to illustrate more clearly the construction ofthe arc chamber and the stationary contacts;

Figure 3 is a side elevational view of the device shown in Figure 2,taken along the line 3 3 thereof;

Figure 4 is a view similar to Figure 3, illustrating the manner in whichone of the split parts of i the insulating housing is removed; and

Figure 5 is a view along the line 5 5 of Figure 4, showing the splitpart oi.' the housing which is removed.

With reference to the drawings, the switch is designated generally bythe reference character I2 and is arranged to be operated by anactuating electro-magnet indicated by the reference character I3.

The switch I2 and the actuating electro-magnet I3 may be mounted on abase II therein to facilitate the anchoring of the entire assembly to asuitable support, The actuating electro-magnet I3may be of any suitabledesign orV construction and is arranged to be ciectrically energized bythe conductors 5ft, and acts to close the switch I2 when energized, in aman ner to be described. The actuating electro-magnet I3 has anoperating member @fl extending upn wardly from one side thereof. Asillustrated, the operating member 4'! is in its lower or retractedposition. The downward travel of the member ci opens the contacts and isarrested by means of the adjustable nuts It.

In the drawings, the switch i2 is arranged to interrupt a three phasecircuit by three sets of contacts designated, respectively, as A., B andC disposed in a split insulating housing. The set of contacts A, B and Cfor the respective phases of the electric circuit are of the sameconstruction and correspondingl parts bear the same reiu erencecharacter. As shown, each set of contacts is arranged to produce adouble-break and comprises two stationary contact means I8 and It! andtwo movable contact means 2U and 2 I. The contact means I8 and 20comprise one pair o1' contacts and the contact means I9 and 2| I0 havingholes pair of contacts consisting -means IB and comprise a recess vupper end of the recess comprise another pair of contacts'. The pair ofcontacts consisting of the contact means I9 and 2l are disposed closerto of the contact means i3 and 20. The movable contact means 20 and 2lare connected together by a bridge member 53. As illustrated best inFigure 2, the bridge memthe base It than the bers 53 for the respectivephases A, B and C are arranged to be simultaneously'actuatedby a motiontransmitting means i3 which isl actuated by the member I1 of theactuating electro-magnet i3.

Each of thefpair of contacts is arranged to be interrupted in a splitinsulating housing comprising two partsv 22 and 23. The part 22comprises an insulating `support member and the part 23 comprises aninsulating body member adapted to be detachably connected tothelinsulating support member by screws i5 which extend through holes 51in the insulating body member 23. The insulating support member and theinsulating body member have mating wall surfaces it and I1,respectively, abutting against each other and forming the, split betweenthe members. The split insulating housing has individual arc chambersfor each of the pair of separable contacts. The arcs chambers aredesignated by the reference characters 2d and 25. The arc chambers 2drespectively enclose the stationary contact 4I and the arc the bridgemember 53 chambers 25 respectively enclose the stationary Y contactmeansi and comprise a recess B2. The

portion 43 which is part of the mating split wall I6 or the insulatingsupporting housing 22. Similarly, the upper end of the recess 42 for thestationary contact means I9 is closed by a wall portion 4e which'alsocomprises a part of the mating splitwall IB of the insulating supportinghousing' 22. The lower end of the recess 4I is'provided 4i is closed bya wall` with an opening 39 in which the movable contact means 20 isoperated by the motion transmitting means I4. The Alowermost 'end isprovided with an opening 40 in which vthe movable' contact means 2l isoperated by the motion transmitting means I4. The stationary contactmeans I8 and I9 are of the same construction and comprise a post 2Ehaving a terminal extension 21 provided on the upper end e thereof andhaving a replaceable contact element 32 removably mounted on the lowerend thereof. The terminal extensions 21 extendthrough openings` in' theinsulating support member 22 4and are securely fastenedto the insulatingsupport member 22 by terminal nuts 28. A shoulder 29 which is providedbetween `the post 26 and the terminal extension 21 rests against awasher 3 0 which is embedded in the insulating support member 22. Thelower end of the post 261s provided with a reduced threaded portion 3|and. is arranged to threadably engage a replaceable contact element 32.The underneath side of the replaceable contact element 32 may beprovided of the recess 42 anchored to the base I0 by means of screws I5and the actuating electro-magnet I3 may be anchored to the base I0 byscrews 36. The movable contact means and the motion transmitting meansI6 in their operative position are disposed in the said gap `andobstruct thewithdrawalof the insulating body member 23, so that theremovable insulating body member 23 cannot be is in its operative theirupper ends provided with inturned anges 5e which constitute stops forholding the bridging member 53 within the spring cagei under thecompression of the spring 52. Each side edge of the bridging member 53is provided' with a notch presenting shoulders 55 for engaging the sideedges of thespringcage 5i. The shoulders 55 prevent a lateral movementof the bridging member 53- within the spring cage 5I. As the movablecontact means engage the stationary contact means, the spring 52 iscompressed and thereby assures that all of the pairs of contacts aremaking a. Aresilient pressure engagement. Each of the bridging members53 and the movable contacts carried thereby may be readily removed fromthe spring cage 5I by manually depressing the spring 52 and then turningthev bridge member 53 until at least one of the notches on the side edgeof the bridging member 53 clearsA the inwardly turned flange 54, afterwhich the bridging member may be removed from the spring position. Inother words,-I am able to remove and inspect the movable contactswithout removl ing the housing.

In operation, all of the movable contact means are operatedsubstantially simultaneously by upward movement of the motiontransmitting means with a contact tip member 33 which is arranged ymeans and the end 56 of the operating member 41 to provide a space forthe removal of the removable insulating body member 23. The stationaryinsulating support member 22 may be element l31 ofthe movable -from the`stationary contact I4 for closingI the three phases of the electricalcircuit. Upon the interruption of the movable contact means by adownward movement, a double brea occurs between the line cgnductors 34 iand 35 of each of the phases A, Band C. The interruption occurs uponde-energizing the ace tuating electro-magnet I3, and is made to occurquickly by sudden expansion of the'compressed springs 52 reacting uponthe motion transmitting means `I4 and giving it a quick kick downwardly.As the movable contact means for each pair of contacts is separated fromthe stationary contact means, the arc between the separable contacts isin the recessed arc chamber which houses the pair of contact means. Asthe movable contact meansfor the pair -is quickly withdrawn means, ifthe arc between the contact means is not immediately ruptured, it tendsto follow the movable contact means into the opening through which themovable contact means operates. The movement of motion transmittingmeans vable contact means operates.

dropped downwardly v lating body member 23 the movable contact means isarrested when the adjustable nuts 49 engage the electro-magnet I3. In myinvention, I preferably provide for arresting the movement of themovable contact means in the openings through which the mov- Theseopenings constitute guides for the'movable contact means, which t in theopenings with therebetween, and the small chambers above the movablecontact means when in their downward arrested position, are thereforesubstantially closed chambers. As shown inthe drawings, the post 26 inthe recess 24 projects from the end wall portion 43 thereof into saidrecess to a point therein, whereby the contacts separate in a regionwhich is closer to the opposite end wall of the recess containing thesmall chamber or opening 39 than to the end wall portion 43 constitutingthe top closure 'end for the annular recess. Similarly, thepost 26 inthe recess 25 projects from the end wall portion 44 thereof into saidrecess to a point therein whereby the contacts separate in a, regionwhich is closer to the 'opposite end wall of the recess containing thesmall chamber or opening 40 than to the end wall portion 44 constitutingthe upper closure end for the tannular recess. Inasmuch as the contacts.separate in a region relatively close to the small chambers or openings,the actuating means may quickly withdraw the movable contacts thereinto,whereby the arc is readily extinguished. The motion transmitting meansi4 holds the movable contact means relatively stable so that the movablecontact means maybe adjusted bythe adjustable nuts 49 to be furtherwithdrawn from the said openings. In order that the movable contactmeans may restrict the openings in which they operate when the contactmeans are fully withdrawn, so that the small chamber will be formed, thearea between the movable contact means and the said openings should besmaller than the area of the opening. In other words, the movement ofthe movable contact means is arrested prior to a point where the areabetween the movable contact means and the said opening equals the areaoi the opening. Y

In removing the insulating body member 23, it is rst necessary that themotion transmitting means id and the .movable contact means be removedfrom the gap between the end 56 of the member 4'! and the contact tipmembers 33 of the stationary contact means. of operation, the removableinsulating body member 23 cannot be removed in thev normal operativeposition of the motion transmitting means. However, the motiontransmitting means may be readily removed by detaching the movable crossarm 4S from the member 41 by taking out the screws 48. When the motiontransmitting means i4 and the movable contact means carried thereby areremoved then the removable insulating body member 23 may be withdrawn orinto the gap between the end 56 of the member 4l and the contacttipmembers 33, as shown in Figure 4. The insulatmay then be removedlaterally, whereupon the stationary contact means are readily accessiblefor inspection andreplacement. Instead of using the screws 48, asuitable hinge construction may interconnect the member 4l and themovable cross arm 46, whereby the motion transmitting means I4 and themovable contact means may be removed from the gap by merely operatingthe hinge construction.

Ingmy invention, the springs 52 are disposed a small clearance To insuresafety I externally of the insulating housing so that they are free fromthe iniluence of the arc in the arc chambers. In other words, thesprings 52 are free from heat or other damaging influences, or burning,which would otherwise occur if they were mounted within the arc chambersor otherwise exposed to the are in the arc chambers.

Although I have described my invention with a certain degree ofparti'cularity, it is understood that the present disclosure has beenmade only by way of example and that numerous changes in the details ofconstruction and the combination and arrangement of parts may beresorted to without departing from the spirit and the scope oi' theinvention as hereinafter claimed.

What is claimed is:

1. In combination, a quick-acting circuit interrupting switch having atleast a iirst and ay second pair of separable contacts, each of said'4pair including a stationary a movable contact means, a

contact means and base, a split insulathaving at least a first arc pairof contacts and a second arc chamber for the second pair of contacts,mounted on the base for quickly operating the movable contact means toeffect a quick circuit interrupting movement, said split housingcomprising an insulating support member and a readily removableinsulating body member adapted to be detachably connected to theinsulating support member, said insulating body member having at least afirst recess constituting a portion oi the first arc chamber and asecond recess constituting' a portion of the second arc chamber, saidinsulating body member also having iirst and second openings connectingthe ilrst and second recesses respectively to the outside of the split"housing, said movable contact means for the first and second pair ofcontacts being movable respectively in said openings upon the actuationthereof by the actuating means, said insulating members having matingWan surfaces abutting against each other and .forming the split betweenthe said members, wall surfaces extending transversely of the saidrecesses, said stationary -contact means for each pair having a irst endportion mounted to the said contact element and said movable contactmeans for each pair having abutting contact surfaces between whichcurrent is interrupted, the stationary contact means for said first pairof contacts being disposed closer to said base than the stationarycontact means for said second pair of contacts, said second end portionfor each stationary contact means projecting from said insulatingsupport member into said recess respectively and extending beyond saidsplit, whereby said second end portions and the contact elementsprovided thereon for said 'pairs of stationary contact means are readilyaccessible upon removal of the insulating body member, and stop means toprevent the said movable contact means from being withdrawn from saidopenings in the insulated body member during the circuit interruptingmovement.

2. In combination, a switch having stationary contact means and movablecontact means, a split housing having a iirst and a second chamber forthe contact means, said second chamber being smaller than the rstchamber and comprising an opening extending from the first chamber tothe outside of the housing, said split actuating mechanism said matingaerien housing comprising an insulating support member and. a readily'removable insulating body member having an annular internal wall constituting a portion of the first chamber, an elongated element mountedon the insulated sup port member and having a projection portion ex-4tending into said iirst chamber toward the second chamber, saidprojection portion supporting the stationary contact means upon the endthereof, said internal annular wail of the nrst chamber and the externalsurface of the sta= `tionary contact means and-the projection portion ofthe saidelongated element denning an annularA recess extending from thestationary contact means toward the insulating support member and awayfrom'the second chamber, actuating means for initially 'separating themovelongated element mounted on the said 'rst end able contact meansfrom the stationary contact means in the first chamber, said actuatingmeans quickly withdrawing the movable contact means into said secondchamber, means for arresting the movement of the movable contact meansin the second chamber, whereby an arc drawn between the contact means isconned substantially in said chambers, said insulating members havingmating wall surfaces abutting against each other and forming the split-between. said members, said mating wall surfaces extending transverselyof said iirst chamber, said projection portion ot said elongatedelement-projecting trom said insulating support member into said nrstchamber and extending beyond said split, whereby said stationary contactmeans is readily accessible upon removalof the insulating bodymember-'trom the insulating support member.

3. in combination, a switch having stationary contact means and movablecontact means, a housing-having a nrst and a second chamber wall portionand having a projection portion extending into said liirst chambertoward the second chamber, said projection portion supporting thestationary contact means upon the end thereof, said internal 'annularwall portion of the rst chamber and the external. surface of thestationary contact means and the projection portion v of the saidelongated element defining an elon= gated annular recess extending fromthe stationary contact means toward the nrst end wall portion and awayfrom the second chamber, actuating means for initially-separating themovable contact means from the stationary contact means in the rstchamber, said actuating means quickly withdrawing the movable contactmeans into said second chamber, and means for arresting the'movement ofthe movable contact means v in the second chamber, whereby an arc drawnbetween the contact means is conned substan tially in said chambers,'said projection vportion of the elongated element projecting from thesaid rst end wall portion into said rst cham- .loer to the pointthereinwhereby the contact means separate in a region which is closer tosaid second end wall portion containing the second chamber than totherst' end wall portion constituting an endfor the said annular recess.

